Quantitative analysis of the microstructure of near β titanium alloy during compression tests

Near β titanium alloys present better formability at moderate temperatures compared to α–β alloys. On the other hand, the strength of the forged workpiece is markedly increased after heat treatments by α-phase precipitation hardening. These properties make these high strength Ti-alloys attractive for aircraft and aerospace components. In this work, the formability of Ti–10V–2Fe–3Al is studied. Hot compression tests with cylindrical specimens are performed by means of a Gleeble® 1500 machine at temperatures below β-transus (788 °C) and at constant strain rates of 0.01, 0.1 and 1 s−1. The flow curves show a continuous softening at 0.1 and 1 s−1 after an initial stress peak, and steady flow at low strain rate (0.01 s−1). The evolution of the microstructure for specimens deformed to different strain levels is examined. A quantitative analysis of SEM images is carried out to determine the distribution, shape and content of α phase before and after deformation. The local strain within the compression specimens is determined by a finite element method and correlated to the microstructure.